对齐表格行中的单元格内容 - 在线编辑器

          <!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>蜜蜂教程(mifengjc.com)</title>
  <script>
    function leftAlign() {
      document.getElementById('header').align = "left";
    }
  </script>
</head>
<body>

  <table width="100%" border="1">
    <tr id="header">
      <th>Firstname</th>
      <th>Lastname</th>
    </tr>
    <tr>
      <td>Peter</td>
      <td>Griffin</td>
    </tr>
  </table>
  <br>
  <input type="button" onclick="leftAlign()" value="内容向右对齐" />
  <p><b>注意:</b>该实例不适用IE浏览器。</p>

</body>
</html>
        